Philip p



(No Model.)

P. F. KRUG.

ELECTRIC ARC LAMP.

No. 601,268. Patented Mar. 29, 1898.

/NVEN TOR A TTOHNE Y5 W/TNESSES UNITED STATES PATENT OFFICE.

PHILIP F. KRUG, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO ERNEST UN GER, OF SAME PLACE.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 601,268, dated March 29, 1898.

Application filed January '7, 1897. Serial No. 618,233. (No model.)

To aZZ whom it may concern.-

Be it known that I, PHILIP F. KRUG, a citizen of the United States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Electrio-Arc Lamps, of which the following is a specification.

This invention has reference to that class of electric-arc lamps which are used in con- 1 o nection with stereoscopes and other scientific apparatus in which a constant focus of the are is required.

The object of the invention is to provide an electric-arc lamp which can be used with the I 5 alternating current or which can, by substituting or interchanging for one part thereof another part, be used for the direct current, and to provide means for setting the lamp in any suitable position relative to the appara- 2o tus with which it is to be used.

The invention consists of an electric-arc lamp which comprises a supporting-stand, a supporting-arm, means for adjusting the arm on the supporting-stand, a guide-rod carried 2 5 by said arm and extending above and below the same, cross-pieces at the upper and lower ends of the guide-rod, a set-screw carried by said guide-rod and adapted to be adjusted against the base of the stand, a screw-spindle provided with actuating means and adapted to rotate in said cross-pieces, while the upper and lower portions of this spindle are respectively provided with opposite screw-threads, correspondingly-threaded supporting-brack- 3 5 ets guided on said guide-rod, and the holders for the upper and lower carbons carried by said brackets.

In the accompanying drawings, Figure 1 is a front elevation of my improved electric-arc 4o lamp, showing the brackets of the carbonholders in section. Fig. 2 is a vertical cen tral section of the lamp. Fig. 3 is an enlarged cross-section on line 3 3, Fig. 2. Fig. 4. is a broken detail cross-section on line 4 4, Fig. 2;

5 and Fig. 5 is a modified form of the screwspindle shown in Fig. 2 and which is substituted therefor when the lamp is to be used for direct currents.

Similar letters of reference indicate corresponding parts.

Referring to the drawings, A represents the supporting-stand of my improved electric-arc lamp, the same being provided with a base A, by which the stand is supported.

B 13 represents a pair of parallel guide-rods, 5 5 which are connected together at their upper and lower ends by means of cross-pieces C C, respectively, said rods being fixed at their intermediate portions to a supporting-arm D, which carries a transverse movable or adjust- 6o able fulcrum e, that works in vertical slots at in the sides of the supporting-stand A, said fulcrum being rocked or oscillated by means of a knob E at its outer end. Fixed on the fulcrum, so as to give size and strength thereto, are a suitable number of sleeves 0. Set into the lower end of the tubular guide-rod B is a screw-nut 0 into which is screwed the threaded portion of an elongated settingscrewF, which is provided with a head f, from which projects a point or teat f, which is adapted to engage into one of the series of sockets or recesses a, formed in the upper side of the base of the stand A.

The brackets G G for the upper and lower carbon holders II II, respectively, are provided with bores or openings, through which the guide-rods B pass,whereby the supporting-brackets are adapted to be moved along the guide-rods, to which end the said supporting-brackets are respectively provided with oppositely-threaded bores or openings g g, with which threaded openings the correspondingly-threaded screw-spindles I engage, so that when said screw-spindle is rotated the supporting-brackets and the carbon-holders will be moved together, either up or down, according to the direction in which the screwspindle is turned. The screwspindle, as shown in Fig. 2, consists of an upper section 0 I and a lower section 1 which are adapted to be coupled together by means of a tongue or projection 2' at the lower end of the upper section I, which fits into a correspondinglyshaped socket or recess 7) in the upper end of 5 the lower section 1 said spindle being turned from its upper end by means of a knob 71 The relative position of the coupled ends of the sectional screw-spindle is such that said coupled ends will be contained within the transverse bore or opening d, formed in the supporting-arm D, so that said screw-spindle IOO becomes practically one piece, and no key or other intermediate positive connection is necessary, as when one section is rotated the other section will also be rotated.

As shown in Fig. 4, each supportin g-b racket B B is provided with a shoe J, having a convex or segmental face corresponding with the contour of the screwspindle and pressed through a lateral opening in the side of each bracket by means of a flat springj, fixed to the bracket. These shoes J, being pressed toward the screw-threaded bores or openings 9 g of the supporting-braekets, engage by their inner ends into the grooves between the screw-threads, the consequence being that when the screw-spindle is rotated, said shoes J acting as nuts that are carried by the sup porting-brackets, in one or the other direction the supporting-brackets G G will move along the guide-rods B B, but in opposite directions, owing to the screw-threads of the respective portions I 1 being formed as right and left screw-threads, respectively. In order to prevent the longitudinal displacement of the screw-spin dle and to permit at the same time the rotation thereof, means are provided which consist, as shown in Fig. 3, of a shoe 7a, which works through a correspondinglyshaped side portion in the upper cross-piece 0, connecting the guide-rodsB B, said shoes being pressed inwardly by means of a springplate K,which is screwed to said cross-piece, whereby the inner concave end of the shoe is pressed into an annular groove 7t, formed in the upper end of the screw-spindle. The pressure of the springs j and K on the shoes J and 7t is relieved by means of headed pushpins L L, respectively, for in order to remove the screw-spindles, as is sometimes necessary, it is necessary to press in upon the push-pins L L, so as to disengage the shoes from the spindle, said screw-spindle being then readily pulled out. The lower end of the screw-spindle is preferably formed with a smooth neck or extremity iiwhioh turns in an opening in the lower cross-piece C,which thereby acts as a step-bearing for the screwspindle.

The form of screw-spindle described, in which the screw-threads are of the same pitch, is to be used for the alternating current, as the simultaneous movement of the carbenholders at the same speed is thereby produced; but when the direct current is used the form of screw-spindle shown in Fig. 5 is substituted. This screw-spindle is also formed in two sections, if desired, but the upper portion of the same is provided with a screwthread so of less pitch than the screw-thread as of the lower portion, the pitch of the lower portion being twice that of the upper portion, so that the lower carbon is caused to move at twice the speed of the upper carbon. This spindle shown in Fig. 5 is preferably formed in one piece, as in full lines, but it may be formed in two pieces, as shown in dotted lines, so as to facilitate the introduction of senses the same into the apparatus described. I'laving two spindle-sections, such as 1 I both being provided with screw-threads of an opposite but of the same pitch, it is only necessary in order to adapt the lamp for the direct current to interchange or substitute the part I for another part of one-half the pitch of the lower part 1 Thus to adapt the lamp for a different current to that for which it is being used it is accomplished by removing a section having a thread of one pitch and replacing it by a section having a thread of different pitch without requiring any especial adjustment to accommodate the different section.

he apparatus is adjusted as follows: Vhen it is desired to raise or lower the lamp, so as to raise or lower its focus, the set-screw F is adjusted to the predetermined point, and the movable fulcrum c is thereby moved in the slots to of the supporting-stand. \Vhen the desired height of the focus is obtained, the lamp is slightly raised bodily by moving the fulcrum c upwardly in the side slots and then rocking the lamp on the said fulcrum and setting the teat or projection F of the set screw into the proper recess or socket a, so that the proper angle with the parts in rela tion to the supporting-stand of the carbons is obtained. The weight of the lamp is mainly imparted to the base of the stand through the medium of the set-screw F, inasmuch as the part c is only the fulcrum on which the lamp is rocked for securing the angular adjustment and by which the lamp is supported against lateral displacement, excepting in so far as it is intentionally brought about by the setting of the teat or projection of the set screw into one or the other of the recesses or sockets of the supper-ting-stand. This forms a very simple, quick, and accurate means of adjustment of the lamp in these two positions.

lit has been described how the arc is kept in focus by the simple rotation of the screwspiudle l, and it may be only necessary to further state that for the axial adjustment of the upper and lower carbon, so that the same will be in the same line, I have provided means which are similar to those shown and claimed in my copending application, Serial No. 600,225, iiled October 17, 1806, and which consists of angular outer portions M M, which are supported at their inner ends in the brackets G a, respectively, said angular portion 11 being adapted to be adjusted in lateral direction by reason of its swiveled connection at m with the supporting-bracket G by means of a set-screw m, while the upper carbon is adjusted in and out from the bracket by means of a screw-nut h, which enwith the threaded shank 7L of the upper -carbon holder ll. The lower 7 carbon gages holder ii and its angular bracket M are for the purpose, as in my aforesaid application, of neutralizing the concussions formed by the upper arc of the lower carbon, cushioned by means of a spring N, which is coiled around the shank of the angular portion M, which works and is retained in an opening in the outer end of the lower bracket G.

By means of the described mechanism the focus of the lamp can be set into any required position relatively to the apparatus with which the lamp is used simply by adjusting the lamp in its various positions by means of the described mechanism.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is l 1. In an electric-arc lamp, the combination with a supporting-stand, of a-supporting-arm provided with a movable fulcrum bearing against said stand, carbon-holders, means for supporting and adj Listing-the carbon-holders, and means for setting and adjusting said supporting-arm and its fulcrum, substantially as set forth.

2. In an electric-arc lamp, the combination with the stand provided with slotted side portions, of a supporting-arm with a fulcrum guided in the slots of said stand, the carbonholders, means for supporting the carbonholders from the supporting-arms, and means for adjusting the said arm and its fulcrum, substantially as set forth.

3. In an electric-arc lamp, the combination with a stand provided with a base having a series of sockets or recesses and with slotted sides, of a supporting-arm provided with a movable fulcrum guided in the slots of the stand, carbon-holders supported from the said arm, and a set-screw for adjusting the said arm and the fulcrum, the lower end of said set-screw being adapted to engage in one of brackets guided on said guide-rods, the carhon-holders carried by said brackets, a screw spindle provided. at its upper and lower ends with oppositely-formed screw-threads respectively received in openings of the brackets,

spring-actuated shoes carried by the brackets and working through the openings therein for engaging with the screw-threads of the spindle, and an additional spring-actuated shoe carried by the upper cross-piece and adapted to engage in an annular groove in the screwspindle, substantially as set forth.

5. In an electric-arc lamp, the combination, with parallel guide-rods, cross-pieces connecting said guide-rods, and brackets for the carbon-holders guided on said rods, of a spindle extending through said brackets and consisting of two, longitudinally-detachable, interlocking and non-fastened parts or sections having respectively right and left screwthreads and one of them being removable from the lamp, the spindle-opening in the top crosspiece being slightly greater in diameter than the threaded portion of the spindle, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

PHILIP F. KRUG.

WVitnesses:

GEO. W. JAEKEL, C. E. GAs'r. 

